AQP4-M23 Full-Length Membrane Protein Products

AQP4-M23 is a major short isoform of aquaporin-4 (AQP4). Translation initiates at Met23, resulting in the absence of the first 22 N-terminal amino acids present in M1. Although this difference does not alter the characteristic six-pass transmembrane water-channel architecture, it has a major impact on AQP4 supramolecular organization. AQP4 monomers assemble into tetramers, and M23-containing tetramers have a strong tendency to further associate into large two-dimensional orthogonal arrays of particles (OAPs). Increasing the relative amount of M1 generally limits OAP growth, making M23 particularly relevant for studies of AQP4 higher-order assembly, OAP formation, and M1/M23-dependent membrane organization.

OAP formation is also highly relevant to antibody research. In AQP4-IgG-positive neuromyelitis optica spectrum disorder (NMOSD), pathogenic autoantibodies recognize conformational extracellular epitopes on AQP4. Some antibodies show substantially stronger binding to M23-rich OAPs because higher-order arrays provide additional composite epitopes spanning neighboring AQP4 tetramers. Recent structural studies have further defined tetramer- and OAP-dependent AQP4 autoantibody recognition, providing a molecular basis for investigating native AQP4 epitopes and NMOSD mechanisms, Explore the latest progress of AQP4-targeted drugs…

Compared with M1-focused products, full-length AQP4-M23 proteins are particularly suited for OAP-related and higher-order conformation studies. DIMA BIOTECH provides full-length human AQP4-M23 Nanodisc proteins in Synthetic Nanodisc, PeptiNanodisc, and biotinylated formats, supporting AQP4-M23 antibody screening, AQP4-IgG binding studies, M1/M23 isoform comparison, and drug discovery.